Rotor balancing

A counterweight for a rotor of a dynamoelectric motor comprising: a main body portion of substantial mass, said main body portion being generally of a shape so as to extend generally circumferentially along an end face of a rotor through an arc of up to but not exceeding 180.degree. of said end face; and mounting means extending outwardly from opposite ends of said main body portion so as to extend generally circumferentially along said end face of said rotor, said mounting means and said main body being of a length so as to extend in excess of 180.degree. around said circumference of said rotor when assembled thereto.

A rotor for use in a rotary machine having a rotatable shaft to which the rotor is attached, the rotor having opposite ends with a plane incorporating the rotor axis dividing the rotor into two imaginary halves, comprising, a counterweight secured to one end of said rotor and including a body having a pair of mounting flanges, said body being disposed entirely on one side of said plane, said flanges extending to the other side of said plane, and means securing said flanges to said one end of said rotor.

A rotary machine comprising a motor including a stator and a rotor, said rotor being secured to a shaft, and a counterweight mounted to one end of the motor for balancing the assembly against forces arising from rotation of the shaft, characterized in that said counterweight extends around said rotor ion excess of 180.degree..